SIFR Alternative - Update
First off, I fixed Ian's bug, where some headings scrolled when highlighted by dragging the mouse. Secondly, I have greatly refined the process by which you specify which heading elements will be replaced, and in the process provided support for multiple fonts. Here's how it works:
1) Specify the path to your fonts in a css font or font-family declaration. Paths must be in double or single quotes:
font-family:"Swf/FranklinGothicBook.swf", Helvetica, sans-serif;
Note that the font lists still work: if you don't include the JS library, the CSS selector behaves as you'd expect it to, and you'd get Helvetica. Also, inheritance works the way you'd expect it to, and you can override the declaration later in the style sheet or in an inline style.
As always, let me know what you think of the demo!